All proof silver dollars are silver dollars, but not all silver dollars are proofs.
That's because proof coins are specially struck for collectors, while (at least up till 1935 in the US) regular silver dollars were struck for use in ordinary commerce.
Please see the Related Question for more details.
The difference is in the 'S' mint mark which is found on the left side of the coin just above her shoulder. The Type 1 dollar's 'S' is like a blob - it is not well defined and is somewhat fat. On the other hand, the 'S' on the Type 2 dollar is more clearly defined and is clearly an 'S'. The Type 2 dollar is much more scarce than the Type 1 dollar.
One cannot have a theory (theorem) without proof. Theories are explanations (models with uses such as predicting on outcome of an experiment or event) for scientific laws, which only describe the phenomenon. Proof is anything that backs up a hypothesis. When a significant amount of proof is shown, the hypothesis becomes a theory due to it being accepting by the scientific community.
A postulate is something that is accepted as true without proof. A theorem, on the other hand, is something that has been proven and is now being accepted as true.
postulates are rules that are accepted without proof and theorems are true statements that follow as a result of other true statements.
A mint state coin is an ordinary coin struck for circulation, but it hasn't yet been sent to a bank or put into commerce. It may have a few "bag marks" due to banging up against other coins when minted or put into distribution bags, but other than that hasn't been handled by anyone or suffered any other wear. Proof coins are specially struck for collectors. The U.S. Mint's description is "a specially produced coin made from highly polished planchets and dies and often struck twice to accent the design". Proof coins are handled individually by people wearing protective gloves and are packed in sonically-sealed plastic holders to prevent damage.
The 1921 Chapman was a proof version of the Morgan Dollar. Very few were minted and because of this, they command a premium price.
It depends greatly on the year, early silver dollar proof dollars can be worth several thousand dollars, modern silver dollar proofs of common dates might be worth $20 or so for silver scrap.
The current year Presidential Silver Dollar Proof Sets sell for between $75 and $100 on Ebay. They can also be had at local collectible shops.
The value of a 1984 Canadian proof dollar is about $12.
The silver proof 1997-S Kennedy half dollar has an current average value of $15.50.
About $24
the 3 coin proof set with 2 silver proof one dollar coins and one 10 dollar proof gold coin is worth about $550.00 retail the 3 coin proof set with 2 silver proof one dollar coins and one 10 dollar proof gold coin is worth about $550.00 retail
A 40% silver "S" mintmark proof Eisenhower contains .3161oz of pure silver or 8.96128 grams
Depending on the condition, an Eisenhower uncirculated dollar as a value between $10.00 and $20.00, of 2014. The 1971 S Silver Proof is worth the most.
Value for a proof 1962 is $10.00-$12.00
The difference is in the 'S' mint mark which is found on the left side of the coin just above her shoulder. The Type 1 dollar's 'S' is like a blob - it is not well defined and is somewhat fat. On the other hand, the 'S' on the Type 2 dollar is more clearly defined and is clearly an 'S'. The Type 2 dollar is much more scarce than the Type 1 dollar.
Unless it is a "proof" coin (actual silver), it is worth one dollar.